When Mr Barack Obama met then President-elect Donald Trump in November 2016, three days after the latter's surprise presidential election victory, he cautioned that North Korea would pose the most serious challenge for the new administration. Going by what has transpired since, the former president was right on the money.

Within a year of that conversation, both North Korea and the United States beat the war drums. The bellicose Mr Kim Jong Un threatened to rain destruction on American cities with newly acquired intercontinental ballistic missile (ICBM) capabilities, which by last August had reportedly undergone two rounds of successful tests. Unfazed, President Trump responded with his own threat to give Pyongyang a "bloody nose".